WASHINGTON (Reuters) -The U.S. workplace safety agency said it is opening an investigation after two workers were killed and one seriously injured at a Delta Air Lines aircraft maintenance facility at the Atlanta airport on Tuesday.

Delta said the incident happened shortly after 5 a.m. EDT at a facility in Delta's technical operations center adjacent to the Hartsfield-Jackson Atlanta International Airport.

The injured worker remains under medical care following the accident, which involved wheel components that were being disassembled for maintenance and were not attached to an airplane, Delta said.

The U.S. Occupational Safety and Health Administration told Reuters it was opening an investigation. The Federal Aviation Administration said it was in contact with Delta about the incident.

"This news is heartbreaking for all of us," Delta said. "We are now working with local authorities and conducting a full investigation to determine what happened."

Delta said the cause of the accident has not been released.

(Reporting by Brendan O'Brien in Chicago and David Shepardson in Washington; Editing by Caitlin Webber, David Holmes, Rod Nickel and Lincoln Feast.)